Restraining latch



April 23, 1963 H. HIMMELBERGER ETAL 3,086,481

' RESTRAINING LATCH Filed May 21, 1962 2 Sheets-Sheet 1 FIG. 1 FIG. 2

INVENTOR Harold Himme/berger Donald K. Adrian BY W ATTORNE Y April 23,1963 H. HIMMELBERGER ETAL 3,086,481

RESTRAINING LATCH Filed May 21, 1962 2 Sheets-Sheet 2 United StatesPatent 3,086,481 RESTRAINING LATCH Harold Himmelberger, Silver Spring,and Donald K. Adrian, Damascus, Md., assignors to the United States ofAmerica as represented by the Secretary of the Navy Filed May 21, 1962,Ser. No. 196,536 10 Claims. (Cl. 104-250) This invention relates to alatch and more particularly to a restraining latch for restraining amissile in the event of accidental ignition, one object of the presentinvention being the provision of a more useful device of this nature.

The invention is admirably adapted for restraining a missile duringdepot check-out of the missile components, but is of course applicablefor numerous other uses.

Many of the devices heretofore used as restraining latches, for onepurpose or another, comprise cam actuation or detent locking means.However, these devices failed to satisfy the present missile restraintrequirements of dependability, simplicity and visual assurance ofoperation. Therefore, other objects of this invention are the provisionsof a restraining latch which is very simple in construction, assembly,servicing, repair and operation.

A further object of invention is the provision of a restraining latch ofsuch rugged construction as to be failure-proof in the event of missileignition during checkout when the missile is being retained on a teststand.

Another object of this invention is the provision of a restraining latchhaving a visual indicator depicting the extent of latch operation.

A still further object of this invention is the provision of arestraining latch having a positive locking arrangement, quickly andeasily operable.

Various other objects and advantages will appear from the followingdescription of one embodiment of the invention, and the novel featureswill be particularly pointed out hereinafter in connection with theappended claims.

FIG. 1 is a side elevation view of a portion of the missile and itssupporting rail with portions broken away;

FIG. 2 is a vertical sectional view taken substantially along the line2-2 of FIG. 1;

FIG. 3 is a vertical sectional view of the retaining latch in latchedcondition taken substantially along the line 3-3 of FIG; 2;

FIG. 4 is a view similar to FIG. 3 showing the latch in unlatchedcondition, and

FIG. 5 is a transverse section taken substantially along the line 55 ofFIG. 3.

A restraining latch embodying this invention, herein disclosed by way ofillustration, comprises a cammed latch having a plunger which acts as acombination indicator-release mechanism to give positive visualassurance of latch engagement and to provide for a one step latchrelease operation which leaves the latch positioned to receive the nextmissile lug. However, it is to be understood that while this inventionis herein described as a missile lug restraining latch for use on adepot missile test stand, the scope thereof is not limited to missiles,but may, by slight modification be adapted for performing other latchingfunctions, such as on hatches, conveyors, and the like.

Referring to the drawings and more particularly to FIGS. 1 and 2, therestraining latch device 4 is secured to a missile support rail 7 of amissile test stand (no-t shown). The missile 5, to be tested, issupported on rail 7 by one or more lugs 6 and is moved from the left inthe direction of the arrow to a correct position for testing such thatthe lug 6 passes by the latch device 4 and is prevented -from returnmotion to the left by latch stop '13. Thus in the event of accidentalignition of the 'n'iissile, stop 13. of latch device 4 restrainsmovement of the missile which might otherwise result in injury anddamage to personnel and material in the adjacent work areas.

The restraining latch device 4 comprises a housing or support 11 of anydesirable and practical shape to facilitate attachment to the teststand. The housing is provided with a bore 12 therethrough in which alatch stop or locking bolt 13 is reciprocable from an operative latchingposition protruding from the housing as in FIG. 3, to an inoperativeunlatched position shown in FIG. 4.

The upper surface of housing 11 is covered by a plate 14 firmly attachedto the housing by screws 16 and provided with a bore 17 generallyconcentric with bore 12 of the housing 11 and through which the upperportion 15 of bolt 13 protrudes. Bolt 13 is a two-diameter shaft havingits lower portion 10 slidably fitting in the housing bore 12 and theupper portion 15 of a reduced diameter slidably fitting bore 17 of coverplate 14 and defining, therebetween, a shoulder '18. A coiledcompression spring 19 surrounds the bolt in the space defined by housingbore 12, the bolt upper portion 15, cover plate 14 and shoulder 18 andacts against shoulder 18 to normally urge the bolt to its operativelatching position as shown in FIG. 1.

A knob 21 is secured to the top of bolt 13- by means of threads 22 and23 on said bolt and knob respectively, and is preferably knurled tofacilitate manual grasping for lifiting bolt 13, against the bias ofspring 19, to the inoperative position shown in FIG. 4. A spacing sleeve24 is positioned around bolt 13 between plate 14 and knob 21 therebylimiting the extent of protrusion of bolt portion 10 below housing 11 inresponse to the urging of spring 19.

One side of the bolt lower portion 10 is provided with a surface 26cammed in the direction of movement of missile lug 6 and facing the lugas it moves along rail 7 toward latch 4. As lug 6 encounters surface 26,bolt 13 is cammed upward into housing 11 as shown in FIG. 4.

The opposite side of the bolt lower portion is provided with a latchingsurface 27 perpendicular to the direction of movement of lug 6 andadjacent to the lug when missile 5 is in test posiiton, this restrainingthe return movement of missile lug 6. Proper alignment of bolt surfaces26 and 27 relative to housing 11 is assured by the provision of a groove28 along the periphery of upper portion 15 and extending from the top ofbolt 13 to a point adjacent shoulder 18 in the direction of reciprocalmovement of the bolt. Plate 14 is provided with a protrusion 29 whichextends into groove 28 thereby preventing rotary motion of bolt 13relative to housing 11 as best shown in FIGS. 3 and 5. It should benoted that groove 28 need extend along the length of portion 15 only farenough to permit bolt '13 to retract into housing 11 as shown in FIGURE4.

Bolt 13 is additionally provided with an axial bore 31 extending fromthe top of the bolt through upper portion 15, having its axis parallelto the line of motion of bolt 13 and terminating in a shoulder 32. Asecond bore 33, of smaller diameter than, but concentric with bore 31,extends trom shoulder 32 into lower portion 10 of the bolt. Knob 21 alsohas a bore therethrough concentric with but of smaller diameter thanbore 31 and, when threaded on the bolt, defines a shoulder 38 with bore31. Bolt 13 is further provided with a transverse bore 34 in lowerportion 10 which communicates with both bore 33 and the periphery of thebolt. Transverse bore 34 also communicates with a recess 36, provided inhousing 11, when the bolt is in a normally extended operative position,as shown in FIGURE 3.

Carried in bores 31, 33 and '37 of the device is an indicating-lockingmember 41 in the form of a plunger having a top indicating section 42slidable in bore 37 and a (it normally protruding therefrom, and anintermediate section 43 and bottom locking section 44 slidably fittingin bore 33. A collar 46 is located between top and intermediate sections42 and 43, respectively, slidably fitting and reciprocatable within bore31, limited in extent of movement by shoulders 32 and 38. A coiledcompression spring 47 is telescoped around intermediate section 43 andacts between shoulder 32 and collar 46 to urge collar 46 toward shoulder38 thereby causing the indicating section 42 to normally protrude fromknob bore 3 7 as shown in FIGURE 3.

A reduced diameter portion 48 is located between intermediate section 43and locking section 44 thereby defining an annular recess 51therebetween for purposes discussed hereinafter. The interface 49between the reduced diameter portion 48 and locking section 44 is in theform of a tapered or chamfered cam surface. It should be noted that whenindicating section 42 is protruding above knob 21 and collar 46 is inabutment with shoulder 38, locking section 44 is positioned in alignmentwith transverse bore 34 as best seen in FIG. 3. Alternatively, whenplunger 41 is retracted into bolt 13 such that indicating section 42 isflush with knob 21, recess 51 is in alignment with transverse bore 34 asbest seen in FIG. 4.

Bolt locking relative to the housing is accomplished by the provision ofa locking detent 55 slidably carried in transverse bore 34 and havingboth ends of a rounded configuration as at 52 and 53. Detent 55 is oflonger length than bore 34 such that when either end of the detent isflush with an adjacent end of bore 34, the opposite rounded end of thedetent protrudes from the other end of the bore. Thus, as may be readilyseen in FIG. 3, when detent surface 52 is in abutment with plungerlocking portion 44, detent end 53 protrudes into housing recess 36.Alternatively, when detent end 53 is in abutment with the surface ofbore 12, detent end 52 extends into recess 51 as shown in. FIG. 4.

In operation, the cycle of movements may be most logically described byassuming the bolt to be in extended operative condition, as shown inFIG. 3, however, without the presence of a missile in test position. Inthis orientation, bolt 13 is urged to the operative position by spring19 thus presenting cam face 26 and latch face 27 below the housing.Plunger 4-1 is urged to its uppermost position by spring 47 thuspositioning locking portion 44 in alignment with the transverse bore 34and detent 55 and detent end 53 is lodged in recess 36 thereby lockingthe bolt relative to the housing. It should be specifically noted thatthe plunger indicating section 42 extends above knob 21 thus givingvisual assurance of the locked condition of the bolt. As a missile ismoved along the test stand rail toward the latch device, missile lug 6encounters bolt cam surface 26. Plunger 41 may now be manu' allydepressed against the action of spring 47 by pushing down on theindicating section thus positioning recess 51 in alignment with thetransverse bore and detent. Further movement of missile lug 6 cams bolt13 upward and similarly causes detent 55 to be cammed out of recess 36and into recess 51, as shown in FIG. 4. It should now be noted thatindicating section 42 is flush with the top of knob 21 thus giving avisual indication that bolt 13 is in an inoperative, unlatchedcondition. It should be further noted that manual pressure on theplunger need be maintained only long enough for detent cam face 52 toengage plunger cam surface 49. Detent surface 52 cooperates with plungersurface 49 to cam the plunger to the lower position, shown in FIG. 4,and to hold the plunger in this position relative to the bolt so long asthe bolt is in an unlatched condition.

As lug 6 moves past the bolt, spring 19 urges the bolt to its extendedlatched position. Recess 36 is again in alignment with the transversebore 34 and detent 55, and plunger 41 in response to the urging ofspring 47 moves upward relative to the bolt, thus camming the detentinto d recess 36, locking the detent therein by the alignment of lockingsection 44 with the transverse bore. Indicating section 42 againprotrudes above the knob to visibly indicate the latched condition ofthe bolt.

To release missile lug 6 from its position in abutment with bolt latchface 27, plunger 41 is manually depressed while, simultaneously, knob 21is grasped and lifted upward. The detent is cammed from engagement inrecess 36 into recess 51 as the bolt is lifted, again assuming thecondition shown in FIG. 4 with indicating section 42 flush with theknob. The missile with its lug 6 may now be returned from the testposition along the rail past latch device 4 and upon release, the bolt,plunger and detent return to the latched condition of FIG. 3 ready toreceive the next missile lug.

As may be readily ascertained hereinabove, the operator may easily makea visual determination of the bolt position without resorting toinspection of the bolt latching surface which is located in a virtuallyhidden position within the missile rail.

It will thus be seen that the invention accomplishes its objects andwhile it has herein been disclosed by reference to the details of aspecific embodiment, it is understood that such disclosure is intendedin an illustrative, rather than limited sense, as it is contemplatedthat various modifications in the construction and arrangement of theparts will readily occur to those skilled in the art, within the spiritof the invention and the scope of the appended claims.

What is claimed is:

1. A latch for holding a member having a path of movement in one of twopossible directions which comprises a support relative to which saidmember moves, a locking element carried by said support for movementinto and out of the path of relative movement of said member, meansbiasing said element into said path, said locking element carrying anindicating member movable in a direction parallel to the direction ofmovement of said locking element, bias means for urging said indicatingmember in the same direction as said locking element moves when movingout of the path of said member, means carried by said locking elementand interacting with said support and indicating member for holding saidindicating member when said indicating member is moved in a directionopposed to that of said locking element when the latter moves out of thepath of said member whereby said indicating member protrudes from saidlocking element when said locking element is in the path of said memberand the indicating member is contained within said locking element whensaid locking element is out of the path of said member.

2. The device as set forth in claim 1 further comprising knob meansattached to said locking element and exterior to said support formanually moving said locking element out of the path of said member.

3. The device as set forth in claim 1 wherein said indicating member hascam surfaces, said means carried by said locking element being a detenthaving a cam surface complementary to and engageable with one of thoseon said indicating member, said support having a recess engageable bysaid detent when said locking element is in the path of said member,said detent being movable from a first position in engagement with saidrecess to a second position in engagement with said indicating membercam surface whereby said detent is in said second position when saidlocking element is out of the path of said member.

4. A latch device comprising a housing having an opening therethrough,means in said opening having on one end a latching surface, said meansbeing movable in said opening from a first position wherein saidlatching surface is entirely within said housing to a second positionwherein said latching surface extends outwardly from said housing, saidmeans having a bore, a plunger mounted in said bore having one endnormally extending out of said bore, said plunger being movable relativeto said means in response to movements of said means whereby saidplunger is contained entirely within said bore when said means is insaid first position thereby indicating that said means is in saidposition.

5. The device set forth in claim 4 additionally comprising first biasmeans in said opening for urging said means to said second position, andsecond bias means in said bore for urging said plunger out of said bore.

6. The device set forth in claim 5 further comprising the longitudinalaxis of said bore being parallel to that of said housing opening, saidmeans having a transverse bore connecting said bore and opening andextending in a direction generally perpendicular to said bore andopening, said housing having a recess adjacent to and in alignment withsaid transverse bore when said means is in said second position, detentmeans carried in said transverse bore, said plunger having a portion ofreduced diameter intermediate the ends thereof, said reduced diameterportion being alignable with said transverse bore, and said distancebetween said reduced diameter portion and said recess when the same arein alignment with the axis of said transverse bore being greater thanthe length of said detent whereby said detent is movable from a positionprojecting from one end of said transverse bore into said recess to aposition projecting from the other end of said transverse bore intocontact with said reduced diameter portion.

7. The device as set forth in claim 6 wherein said reduced diameterportion is normally held out of alignment with said transverse bore bysaid second bias means, and said detent means is of greater length thansaid transverse bore, whereby when said plunger is normally extendingout of said bore said detent protrudes into said recess therebyindicating said means is in said second position.

8. The device as set forth in claim 7 wherein at least one end of saidrecess and adjacent end of said detent are cam surfaces, and at leastone end of said plunger adjacent said reduced diameter portion and saidother end of said detent are cam surfaces, whereby movement of saidplunger toward said normally extended position cams said detent intosaid recess, and subsequent relative move ment of said housing and meanscams said detent out of said recess.

9. The device as set forth in claim 8 wherein the surface of saidplunger adjacent said detent is an abutment preventing movement of saiddetent into engagement with said reduced diameter portion when saidplunger is in said normally extended position whereby said detent isheld in said recess thereby locking said means in said second position.

10. The device as set forth in claim 9 wherein said abutment surface onsaid plunger is movable out of engagement with said detent when saidplunger is moved from said normal extended position against said biasmeans into said bore whereby said detent is movable from engagement insaid recess into engagement with said reduced diameter portion therebypermitting said means to move to said first position.

References Cited in the file of this patent UNITED STATES PATENTS1,867,678 Rayburn July 19, 1932

1. A LATCH FOR HOLDING A MEMBER HAVING A PATH OF MOVEMENT IN ONE OF TWOPOSSIBLE DIRECTIONS WHICH COMPRISES A SUPPORT RELATIVE TO WHICH SAIDMEMBER MOVES, A LOCKING ELEMENT CARRIED BY SAID SUPPORT FOR MOVEMENTINTO AND OUT OF THE PATH OF RELATIVE MOVEMENT OF SAID MEMBER, MEANSBIASING SAID ELEMENT INTO SAID PATH, SAID LOCKING ELEMENT CARRYING ANINDICATING MEMBER MOVABLE IN A DIRECTION PARALLEL TO THE DIRECTION OFMOVEMENT OF SAID LOCKING ELEMENT, BIAS MEANS FOR URGING SAID INDICATINGMEMBER IN THE SAME DIRECTION AS SAID LOCKING ELEMENT MOVES WHEN MOVINGOUT OF THE PATH OF SAID MEMBER, MEANS CARRIED BY SAID LOCKING ELEMENTAND INTERACTING WITH SAID SUPPORT AND INDICATING MEMBER FOR HOLDING SAIDINDICATING MEMBER WHEN SAID INDICATING MEMBER IS MOVED IN A DIRECTIONOPPOSED TO THAT OF SAID LOCKING ELEMENT WHEN THE LATTER MOVES OUT OF THEPATH OF SAID MEMBER WHEREBY SAID INDICATING MEMBER PROTRUDES FROM SAIDLOCKING ELEMENT WHEN SAID LOCKING ELEMENT IS IN THE PATH OF SAID MEMBERAND THE INDICATING MEMBER IS CONTAINED WITHIN SAID LOCKING ELEMENT WHENSAID LOCKING ELEMENT IS OUT OF THE PATH OF SAID MEMBER.